The invention is related to an apparatus for the flowthrough treatment of textile material, non-wovens, or paper, with a gaseous or liquid treatment medium circulated within the entire apparatus, comprising a permeable drum as a conveying element subjected to throughflow from the outside toward the inside, said drum being under a suction draft and exhibiting end plates at the end faces, said drum being covered on its periphery with a screen-type cover, sheet metal strips extending in the axial direction being arranged in width of these sheet metal strips running substantially in the radial direction, and connecting elements which connect the sheet metal strips being provided in the peripheral direction between the sheet metal strips and more particularly, to such an apparatus wherein the connecting elements are connecting-locking elements that:
(a) are each of one piece, i.e., have a unitary structure,
(b) are each fashioned with a connecting portion with a width corresponding to the desired spacing of the immediately adjacent sheet metal strips,
(c) are each connected with an adjacent sheet metal strip, and furthermore
(d) are provided at least on one side with a locking element portion which can be, respectively, pushed through a corresponding opening in the associated sheet metal strip.
An apparatus of this type has been described in German Patent Application P 38 02 791.7 and corresponding U.S. Pat. No. 4,811,574. This structure has the advantage of eliminating the conventional, complicated honeycomb arrangement according to U.S. Pat. No. 3,590,453 wherein the drum body is made up of metal strips extending in a zigzag shape in the axial direction and being joined by welding, in such a way that the screen-shaped cover has a honeycomb-like structure. In order to be able to connect the elements of this drum structure with one another, a voluminous welding operation must be performed which is not only expensive with respect to the assembly but also is disadvantageous in that the total construction will be warped on account of the high temperature curing the extensive welding work. For this reason, true-running accuracy of said welded honeycomb structures is possible only by considerable additional work after assembly. The construction according to the above-indicated German patent application proceeds along a different route by placing readily mountable spacers between the sheet metal strips and connecting these spacers with the sheet metal strips by means of screws or rivets. An apparatus of this type has proven to be definitely of advantage under practical conditions, but it cannot be utilized for all applications. In particular, it has been found that the total construction of the drum construction as a considerable weight; actually, such a weight provides a corresponding ruggedness of the arrangement. In case of drums which must be driven at a high speed of rotation, for example for the drying of paper or the production of nonwovens, this screw construction can, however, lead to disadvantages.
The invention is based on the object of finding drum construction which still exhibits the optimum permeability of more the 90%, but yet is simpler in assembly, due to the fact that the known screw construction is avoided, and can yet be manufactured with considerably greater ease while retaining the stability of the total structure.
Starting with the apparatus of the type heretofore described wherein, according to the aforementioned German patent application, a peg-shaped spike is pushed through a corresponding opening in the adjacent sheet metal strip and a nut is screwed onto the spike for fastening this connection element to the sheet metal strip, the invention now proceeds along a different route. The essential basic idea resides in that the locking element portion of each connecting-locking element, pushed through the sheet metal strip, can be fixedly adjusted or fixedly jointed to the adjacent second connectinglocking element, i.e., the connecting portions of this element. Thus, in contrast to the state of the art, the respective connecting-locking element is not joined to one of the sheet metal strips in this arrangement but rather the connecting elements are joined together. The connection can be effected in a simple way by welding; the weld seams need not provide the ruggedness of the total structure over a relatively long length, but rather a short weld seam is sufficient for the force-derived connection of a locking element with the subsequent connecting element. Warping of the total structure thus is precluded thereby.
This basic idea covers quite a number of embodiments, each of which is inventive. For example, the connecting-locking element can advantageously consist merely of a radially extending web having a thickness corresponding to the sheet metal thickness and being additionally provided with a unilaterally located T-flange, the locking element portion that can be pushed through an opening in the sheet metal strip being disposed on the other side of this flange. The locking element portion of this composite connecting-locking element should be fashioned as a bolt which has in its center a slot oriented in parallel to the web and corresponding to the thickness of the web. The mounting of such a web-bolt structure is very simple. It is possible, for example, to preassemble the respective connecting-locking elements with a sheet metal strip, by joining the respective T-flange with the sheet metal strip by a short weld seam. Subsequently, the individual sheet metal strips provided with the connecting-locking elements are pushed radially inwardly into the drum structure, namely in such a way that the radially extending webs are pushed between the halved bolts. The bolts then are to be welded to the webs whereupon a further series of connecting-locking elements can be mounted.
Another, similarly advantageous structure consists in that the connecting-locking element is a pipe with a unilaterally arranged spike which can be pushed through an opening in the sheet metal strip, the outer diameter of this spike corresponding to the inner diameter of the pipe. These connecting-locking elements cannot be displaced radially into the drum structure for mounting purposes but rather must be arranged in a series one behind the other in the peripheral direction, but here again a rugged total construction is attainable without the necessity for extensive welding work and without giving the total structure a considerable weight. the weld seam in this arrangement is merely the connection of the pipe with the spike; this can be accomplished through an opening in the pipe.
Another advantageous connecting-locking element comprises a radially extending web likewise having a thickness corresponding to the sheet metal thickness, but in this case the locking element portio is constituted of a finger-like sheet metal strip which is narrower as compared with the height of the web; this strip can, in turn, be pushed through an opening in the axially extending sheet metal strip and can be welded to the next-following connecting-locking element oriented in parallel to the web. These connecting locking elements thus consist in total only a of a piece of sheet metal which can be punched during manufacture. The respectively adjacent connecting elements thus cover one another in parallel and consequently can be joined into a rugged total structure by a simple weld seam.
The connecting-locking elements, however, can also be fashioned in a manner of snap fasteners wherein the head of the respective snap fastener part corresponds in its width to the desired spacing of the sheet metal strips and has, in its body, a cavity with an opening for the insertion of the round snap fastener pin. In this arrangement, assembly is especially simple because the snap fasteners are suitable joined after assembly to the axially extending sheet metal strips by means of a weld seam.
Heretofore, the connecting element consisted in each case of an element joined to a locking element which was insertable through the axially extending sheet metal strip so that in each case a locking element could be welded to a neighboring connecting element. In a further embodiment, this idea of joining a first space between two axially extending sheet metal strips with the neighboring space tween two sheet metal strips be means of elements extending through both spaces has been further developed in consequent fashion by providing that the locking element can be pushed through more than one of the successive sheet metal strips, for example, by making the connecting-locking element of at least one sheet metal profile extending around the drum, this profile then being welded, during assemblage, to the axially extending sheet metal strips in correspondence with their desired spacing.
The drawings show several embodiments of the apparatus according to this invention. Still further details of the invention will be described in greater detail below with reference to these embodiments; these details are then also of inventive significance in conjuction with the basic construction.